A comprehensive study of УВа2Сиз06+6 oxide, subjected to a "soft" hydration (exposure at small values of рн2о) by a special technique has been performed. The material modified in this way acquires a unique property; namely, it intensively absorbs components of the gas atmosphere: O2, N2, Ar, H20 и CO2. It has been shown that, at least the first four of them enter into the crystal lattice of yttrium-barium cuprate, filling the vacant oxygen positions. Magnetic measurements revealed the coexistence of magnetically ordered and diamagnetic regions in the modified yttrium barium cuprate.